From: Lennart Poettering Date: Tue, 17 Jan 2012 14:04:12 +0000 (+0100) Subject: tmpfiles: add support for creating symlinks, char/block device nodes X-Git-Tag: v39~34 X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=commitdiff_plain;h=468d726bdd0a383713964dec01fc38ca31256d62 tmpfiles: add support for creating symlinks, char/block device nodes --- diff --git a/man/tmpfiles.d.xml b/man/tmpfiles.d.xml index 4a8e8316c..080da6681 100644 --- a/man/tmpfiles.d.xml +++ b/man/tmpfiles.d.xml @@ -67,27 +67,31 @@ Configuration Format Each configuration file is named in the style of - <program>.conf. - Files in /etc/ overwrite - files with the same name in /usr/lib/. - Files in /run overwrite files with - the same name in /etc/ and - /usr/lib/. Packages should install their - configuration files in /usr/lib/, files - in /etc/ are reserved for the local - administration, which possibly decides to overwrite the - configurations installed from packages. All files are sorted - by filename in alphabetical order, regardless in which of the - directories they reside, to ensure that a specific - configuration file takes precedence over another file with - an alphabetically later name. + <program>.conf. Files in + /etc/ override files with the + same name in /usr/lib/. Files in + /run override files with the same + name in /etc/ and + /usr/lib/. Packages should + install their configuration files in + /usr/lib/, files in + /etc/ are reserved for the local + administrator, who may choose to override the + configurations installed from packages. The list of + configuration files are sorted by their filename in + alphabetical order, regardless in which of the + directories they reside, to guarantee that a + configuration file takes precedence over another + configuration file with an alphabetically later + name. The configuration format is one line per path - containing action, mode, ownership and age + containing action, path, mode, ownership, age and argument fields: - Type Path Mode UID GID Age -d /run/user 0755 root root 10d + Type Path Mode UID GID Age Argument +d /run/user 0755 root root 10d - +L /tmp/foobar - - - - /dev/null Type @@ -117,6 +121,21 @@ d /run/user 0755 root root 10d Create a named pipe (FIFO) if it doesn't exist yet + + L + Create a symlink if it doesn't exist yet + + + + c + Create a character device node if it doesn't exist yet + + + + b + Create a block device node if it doesn't exist yet + + x Ignore a path @@ -185,10 +204,11 @@ d /run/user 0755 root root 10d The file access mode to use when creating this file or directory. If omitted or when set to - the default is used: 0755 for - directories, 0644 for files. For z, Z lines - if omitted or when set to - the file access mode will - not be modified. This parameter is ignored for x, r, R - lines. + directories, 0644 for all other file + objects. For z, Z lines if omitted or when set + to - the file access mode will not be + modified. This parameter is ignored for x, r, + R, L lines. @@ -200,7 +220,7 @@ d /run/user 0755 root root 10d omitted or when set to - the default 0 (root) is used. For z, Z lines when omitted or when set to - the file ownership will not be modified. - These parameters are ignored for x, r, R lines. + These parameters are ignored for x, r, R, L lines. @@ -233,6 +253,16 @@ d /run/user 0755 root root 10d is done. + + Argument + + For L lines determines the destination + path of the symlink. For c, b determines the + major/minor of the device node, with major and + minor formatted as integers, separated by :, + e.g. "1:3". Ignored for all other lines. + + @@ -241,7 +271,7 @@ d /run/user 0755 root root 10d /etc/tmpfiles.d/screen.conf example screen needs two directories created at boot with specific modes and ownership. - d /var/run/screens 1777 root root 10d + d /var/run/screens 1777 root root 10d d /var/run/uscreens 0755 root root 10d12h diff --git a/src/tmpfiles.c b/src/tmpfiles.c index 44e5c9d28..209601969 100644 --- a/src/tmpfiles.c +++ b/src/tmpfiles.c @@ -57,6 +57,9 @@ typedef enum ItemType { CREATE_DIRECTORY = 'd', TRUNCATE_DIRECTORY = 'D', CREATE_FIFO = 'p', + CREATE_SYMLINK = 'L', + CREATE_CHAR_DEVICE = 'c', + CREATE_BLOCK_DEVICE = 'b', /* These ones take globs */ IGNORE_PATH = 'x', @@ -70,11 +73,14 @@ typedef struct Item { ItemType type; char *path; + char *argument; uid_t uid; gid_t gid; mode_t mode; usec_t age; + dev_t major_minor; + bool uid_set:1; bool gid_set:1; bool mode_set:1; @@ -656,6 +662,60 @@ static int create_item(Item *i) { break; + case CREATE_SYMLINK: { + char *x; + + r = symlink(i->argument, i->path); + if (r < 0 && errno != EEXIST) { + log_error("symlink(%s, %s) failed: %m", i->argument, i->path); + return -errno; + } + + r = readlink_malloc(i->path, &x); + if (r < 0) { + log_error("readlink(%s) failed: %s", i->path, strerror(-r)); + return -errno; + } + + if (!streq(i->argument, x)) { + free(x); + log_error("%s is not the right symlinks.", i->path); + return -EEXIST; + } + + free(x); + break; + } + + case CREATE_BLOCK_DEVICE: + case CREATE_CHAR_DEVICE: { + + u = umask(0); + r = mknod(i->path, i->mode | (i->type == CREATE_BLOCK_DEVICE ? S_IFBLK : S_IFCHR), i->major_minor); + umask(u); + + if (r < 0 && errno != EEXIST) { + log_error("Failed to create device node %s: %m", i->path); + return -errno; + } + + if (stat(i->path, &st) < 0) { + log_error("stat(%s) failed: %m", i->path); + return -errno; + } + + if (i->type == CREATE_BLOCK_DEVICE ? !S_ISBLK(st.st_mode) : !S_ISCHR(st.st_mode)) { + log_error("%s is not a device node.", i->path); + return -EEXIST; + } + + r = item_set_perms(i, i->path); + if (r < 0) + return r; + + break; + } + case RELABEL_PATH: r = glob_item(i, item_set_perms); @@ -686,6 +746,9 @@ static int remove_item_instance(Item *i, const char *instance) { case TRUNCATE_FILE: case CREATE_DIRECTORY: case CREATE_FIFO: + case CREATE_SYMLINK: + case CREATE_BLOCK_DEVICE: + case CREATE_CHAR_DEVICE: case IGNORE_PATH: case RELABEL_PATH: case RECURSIVE_RELABEL_PATH: @@ -701,8 +764,8 @@ static int remove_item_instance(Item *i, const char *instance) { case TRUNCATE_DIRECTORY: case RECURSIVE_REMOVE_PATH: - if ((r = rm_rf(instance, false, i->type == RECURSIVE_REMOVE_PATH, false)) < 0 && - r != -ENOENT) { + r = rm_rf(instance, false, i->type == RECURSIVE_REMOVE_PATH, false); + if (r < 0 && r != -ENOENT) { log_error("rm_rf(%s): %s", instance, strerror(-r)); return r; } @@ -724,6 +787,9 @@ static int remove_item(Item *i) { case TRUNCATE_FILE: case CREATE_DIRECTORY: case CREATE_FIFO: + case CREATE_SYMLINK: + case CREATE_CHAR_DEVICE: + case CREATE_BLOCK_DEVICE: case IGNORE_PATH: case RELABEL_PATH: case RECURSIVE_RELABEL_PATH: @@ -761,6 +827,7 @@ static void item_free(Item *i) { assert(i); free(i->path); + free(i->argument); free(i); } @@ -790,6 +857,15 @@ static bool item_equal(Item *a, Item *b) { (a->age_set && a->age != b->age)) return false; + if (a->type == CREATE_SYMLINK && + !streq(a->argument, b->argument)) + return false; + + if ((a->type == CREATE_CHAR_DEVICE || + a->type == CREATE_BLOCK_DEVICE) && + a->major_minor != b->major_minor) + return false; + return true; } @@ -804,7 +880,8 @@ static int parse_line(const char *fname, unsigned line, const char *buffer) { assert(line >= 1); assert(buffer); - if (!(i = new0(Item, 1))) { + i = new0(Item, 1); + if (!i) { log_error("Out of memory"); return -ENOMEM; } @@ -815,19 +892,22 @@ static int parse_line(const char *fname, unsigned line, const char *buffer) { "%ms " "%ms " "%ms " + "%ms " "%ms", &type, &i->path, &mode, &user, &group, - &age) < 2) { + &age, + &i->argument) < 2) { log_error("[%s:%u] Syntax error.", fname, line); r = -EIO; goto finish; } switch(type) { + case CREATE_FILE: case TRUNCATE_FILE: case CREATE_DIRECTORY: @@ -839,11 +919,41 @@ static int parse_line(const char *fname, unsigned line, const char *buffer) { case RELABEL_PATH: case RECURSIVE_RELABEL_PATH: break; + + case CREATE_SYMLINK: + if (!i->argument) { + log_error("[%s:%u] Symlink file requires argument.", fname, line); + r = -EBADMSG; + goto finish; + } + break; + + case CREATE_CHAR_DEVICE: + case CREATE_BLOCK_DEVICE: { + unsigned major, minor; + + if (!i->argument) { + log_error("[%s:%u] Device file requires argument.", fname, line); + r = -EBADMSG; + goto finish; + } + + if (sscanf(i->argument, "%u:%u", &major, &minor) != 2) { + log_error("[%s:%u] Can't parse device file major/minor '%s'.", fname, line, i->argument); + r = -EBADMSG; + goto finish; + } + + i->major_minor = makedev(major, minor); + break; + } + default: log_error("[%s:%u] Unknown file type '%c'.", fname, line, type); r = -EBADMSG; goto finish; } + i->type = type; if (!path_is_absolute(i->path)) { @@ -895,7 +1005,9 @@ static int parse_line(const char *fname, unsigned line, const char *buffer) { i->mode = m; i->mode_set = true; } else - i->mode = i->type == CREATE_DIRECTORY ? 0755 : 0644; + i->mode = + i->type == CREATE_DIRECTORY || + i->type == TRUNCATE_DIRECTORY ? 0755 : 0644; if (age && !streq(age, "-")) { if (parse_usec(age, &i->age) < 0) { @@ -909,7 +1021,8 @@ static int parse_line(const char *fname, unsigned line, const char *buffer) { h = needs_glob(i->type) ? globs : items; - if ((existing = hashmap_get(h, i->path))) { + existing = hashmap_get(h, i->path); + if (existing) { /* Two identical items are fine */ if (!item_equal(existing, i)) @@ -919,7 +1032,8 @@ static int parse_line(const char *fname, unsigned line, const char *buffer) { goto finish; } - if ((r = hashmap_put(h, i->path, i)) < 0) { + r = hashmap_put(h, i->path, i); + if (r < 0) { log_error("Failed to insert item %s: %s", i->path, strerror(-r)); goto finish; } @@ -1024,7 +1138,8 @@ static int read_config_file(const char *fn, bool ignore_enoent) { assert(fn); - if (!(f = fopen(fn, "re"))) { + f = fopen(fn, "re"); + if (!f) { if (ignore_enoent && errno == ENOENT) return 0;